Indeed, but NFT enthusiasts would say that the replicas are not valid because they were not originally minted by the trusted author, of course, nothing is stopping the author from minting multiple NFTs of the same content so the point is moot.
Why would you want the minter to be prevented from minting multiple NFRs of the same content? The content is totally moot! It’s the ownership of the scarce token which the author claims uniquely represents the content that people are valuing. Obviously if the author is minting multiple tokens and claiming they all uniquely represent the same piece of content, most likely no one is going to value those tokens much. None of this strikes me as odd or troublesome. It’s how all collectibles have worked long before NFTs.